It was a rainy Friday afternoon, back when I was executive director of the Wyoming Valley Sanitary Authority, a regional wastewater system. We had a long force main along the river that intercepted flow from several municipal pump stations along its route.
Chlorine and chloramines are both effective disinfectants used in water distribution systems. Each has its own advantages and disadvantages, and the debates over their tradeoffs have gone on for decades.
Learn about the 3 most common reasons to flush a water distribution systems: scour solids, move higher quality water, and remove contamination.
Notice that I said system head curve (not curves). We know that the system head curve is not a single curve but a band of curves depending on the water level in the wet well and pressure in the force main. However, for a simple force main, the band of system head curves is narrow as the fluctuations in wet well depth is minimal.
Another issue lies in the personas who are asking and answering the question. Usually the decision maker (i.e. design engineer or system operator) will ask the modeler, “Is this model calibrated?,” and expect the modeler to answer yes or no. What should happen is that the modeler should show the work that was done to calibrate the model to the decision maker and ask, “Do you think the model will meet your needs?”
Create hydraulic structures in a breeze with Bentley’s OpenFlows FlowMaster. Suppose you know the characteristics of a gravity sewer, but you’d like to know the percent full and Froude number when it carries 20 L/s. You can dig out your old hydraulics book, look up the Manning equation, figure out how to iteratively solve it for depth, and write a little program to solve it, and after an hour or so, you may have the answer (if you didn’t make a mistake).
Saving energy is a multi-faceted problem and there is not a single solution. There are plenty of ways of wasting energy and it takes some analysis to determine WHY energy is being wasted before moving on to HOW can you save energy.